Relationship between the quantitative morphometry and the clinical response to alpha adrenergic blocker in benign prostatic hyperplasia

Abstract

(Background) There have been few reports on the relationship between the prostatic tissue components and the effect of alpha adrenergic blocker on urination. The present study was undertaken to correlate the rates of the prostatic tissue components and the clinical response to alpha adrenergic blocker in benign prostatic hyperplasia. (Methods) 40 patients with symptomatic benign prostatic hyperplasia were treated with 0.2 mg/day tamsulosin, a alpha adrenergic blocker, for 4~8 weeks followed by transurethral resection of the prostate. The mean weight of resected prostatic tissues was 25.2 g (range 5~96 g). Specimens were stained with antibodies to muscle-specific actin and to prostate-specific antigen for the detection of the smooth muscle and the glandular epithelium, respectively. Double-immunoenzymatic stained tissue sections were divided into four groups: smooth muscle, connective tissue, glandular epithelium, and glandular lumen. The rates of the areas of respective prostatic tissue components were evaluated with computer-assisted quantitative color image analysis. (Results) The mean rate of the area of smooth muscle, connective tissue, glandular epithelium, and glandular lumen was 32.7%, 46.9%, 10.8%, and 9.6%, respectively. International prostatic symptom score, maximum flow rate and residual urine volume before the treatment were not related to the rates of respective prostatic tissue components. International prostatic symptom score and residual urine volume were reduced and maximum flow rate was increased after the treatment with tamsulosin. A significant relationship was proved between the rate of smooth muscle and the change in maximum flow rate. The large hyperplastic adenoma contained less smooth muscle and showed a lower sensitivity to alpha adrenergic blocker than the small one. (Conclusion) The clinical response to alpha adrenergic blocker was related to the rate of smooth muscle in benign prostatic hyperplasia.